Field of the Invention
The present invention relates to an optical fiber terminal fixing tool for fixing a winding start end of an optical fiber to a bobbin and a method for winding the optical fiber on the bobbin using the fixing tool at the time of winding start when the optical fiber is wound around a winding portion between flange portions of the optical fiber winding bobbin having the flange portion. Particularly, the present invention relates to an optical fiber terminal fixing tool suitable for introducing an optical fiber having a terminal fixed to a bobbin to a winding portion, and a winding method using the fixing tool.
Priority is claimed on Japanese Patent Application No. 2013-138935, filed on Jul. 2, 2013, the content of which is incorporated herein by reference.
Description of Related Art
In a manufacturing method for an optical fiber wire, a manufacturing method for an optical fiber core wire, or the like, the optical fiber wire or the optical fiber core wire is wound around a bobbin. Moreover, hereinafter, the optical fiber wire and the optical fiber core wire are collectively referred to as an optical fiber. As the bobbin, a bobbin in which flange portions are provided on both ends of a winding portion (a so-called winding drum) having a cylindrical shape is used. Generally, first, the bobbin is mounted on a winding machine, and a tip portion of the optical fiber to be wound is fixed to the bobbin or a portion which is integrally rotated with the bobbin. Moreover, the bobbin is rotated while tension (winding tension) is applied to the optical fiber, and thus, the optical fiber is wound around an outer circumferential surface of the winding portion (winding drum) between flange portions.
Here, when the winding of the optical fiber starts, as described above, it is necessary to fix the tip portion of the optical fiber to be wound to the bobbin or the portion which is integrally rotated with the bobbin. In this case, generally, the tip portion of the optical fiber is inserted between an outer surface of the flange portion of one end side of the bobbin and a surface of the winding machine side opposing the outer surface. In this case, a terminal of the optical fiber is fixed to the outer surface side of the flange portion. Accordingly, in order to wind the optical fiber around the winding portion inside the flange portion, at the beginning of winding start, the optical fiber needs to cross over the flange portion from the outer surface side of the flange portion and to drop on (i.e., to be introduced to) the outer circumferential surface of the inner winding portion.
In this way, as a method which fixes the terminal of the optical fiber to the outer surface side of the flange portion and introduces the optical fiber to the outer circumferential surface of the winding portion inside the flange portion, particularly, as a method for automatically performing the introduction, for example, a method disclosed in Japanese Unexamined Patent Application, First Publication No. 2000-72329 is widely adopted. The method of the related art is schematically shown in FIGS. 21 to 23.
In FIGS. 21 and 22, in a bobbin 1, flange portions 5A and 5B having larger diameters than an outer diameter of a winding drum 3 are formed on both ends in an axial direction of the winding drum (winding portion) 3 having a cylindrical shape. Meanwhile, a disc-shaped fixed plate 9 which is integrally rotated with a rotating shaft 7 is provided on the rotating shaft 7 of the winding machine. Moreover, the bobbin 1 is mounted on the rotating shaft 7 of the winding machine so that the plate surface of the fixed plate 9 and the outer surface of the flange portion 5A oppose each other. Meanwhile, an optical fiber 11 is supplied to the bobbin 1 via a guide roller 13 such as a traverser. Moreover, in a step before the winding starts (before the bobbin is rotated), a tip portion of the optical fiber 11 to be wound is interposed so as to be fixed between the fixed plate 9 and the flange portion 5A. Moreover, a lateral movement member 15 for regulating a traveling position of the optical fiber 11 supplied from the guide roller 13 of the traverser to the bobbin 1 is disposed in the vicinity of the outer circumference of the flange portion 5A. In an initial step, the lateral movement member 15 moves toward the other flange portion 5B in parallel with a rotation axis of the bobbin 1. Accordingly, the optical fiber 11 crosses over the flange portion 5A and drops on the outer circumference of the winding drum 3. Moreover, as shown in FIG. 23, an introduction groove 17, which is notched from the outer circumferential edge of the flange portion 5A to the inner side, is formed on the outer circumferential portion of the flange portion 5A. If the bobbin 1 is rotated, the optical fiber 11 laterally moved by the lateral movement member 15 is caught on the introduction groove 17 at a boundary portion between an outer circumferential edge surface 5Aa of the flange portion 5A and a bottom surface of the introduction groove 17. Thereafter, the bobbin 1 is further rotated, and thus, the optical fiber 11 can drop on the outer circumferential surface of the winding drum 3 inside the flange portion 5A from the introduction groove 17.
In addition, in a manufacturing process or the like of the optical fiber, a bobbin 20 shown in FIG. 24 may be used. In the bobbin 20, a first winding portion (hereinafter, referred to as a narrow width winding portion, and generally, a width W1 is approximately several millimeters) 21 having a cylindrical shape in which the width W1 in a direction along the rotation axis is very narrow and short, and a second winding portion (hereinafter, referred to as a wide width winding portion, and generally, a width W2 is tens of millimeters or more) 23 having a cylindrical shape in which the width W2 in the direction along the rotation axis is considerably wider than the width W1 of the narrow width winding portion 21 are formed so as to be integrated in series with an intermediate flange portion 25B as a boundary. That is, the narrow width winding portion 21 is formed between a first flange portion 25A positioned at one end side (one end side in the direction along the rotation axis) of the entire bobbin 20 and the intermediate flange portion (second flange portion) 25B, and the wide width winding portion 23 is formed between a third flange portion 25C positioned at the other end side of the entire bobbin 20 and the intermediate flange portion (second flange portion) 25B. Moreover, a diameter d1 of the first flange portion 25A outside the narrow width winding portion 21 is smaller than diameters d2 of both flange portions (the second flange portion (the intermediate flange portion) 25B and the third outer flange portion 25C) of the wide width winding portion 21.
Generally, the narrow width winding portion 21 of the bobbin 20 is used to wind a portion for measuring characteristics of the optical fiber. That is, a portion (approximately several meters) of the terminal side of the optical fiber is wound around the narrow width winding portion 21 at the initial step after the winding starts, and thereafter, most of the remaining optical fiber is wound longer around the wide width winding portion 23. In addition, generally, in order to perform the characteristic measurement of the optical fiber wound around the bobbin, the portion wound around the narrow width winding portion 21 is used.
As described above, when the optical fiber is wound around the winding portion 21 having a very narrow width, in the case where the method of the related art shown in FIGS. 21 to 23 is applied, for practical purposes, in most cases, the winding is difficult. The reason will be described with reference to FIG. 25.
When the lateral movement member 15 positioned at the outer circumferential side of the second flange portion (intermediate flange portion) 25B having a larger diameter is moved in a direction of an arrow 26 and the optical fiber 11 is pressed by the lateral movement member 15, before the optical fiber 11 crosses over the first flange portion 25A in order to be shifted (before an angle of the optical fiber 11 with respect to the first flange portion 25A is a certain value), the optical fiber 11 abuts a corner (a circle portion 24 in FIG. 25) of the second flange portion 25B. Accordingly, the angle of the optical fiber 11 with respect to the first flange portion 25A cannot be changed, and thus, the optical fiber 11 cannot drop into the narrow width winding portion 21 between the first outer flange portion 25A and the second intermediate flange portion 25B.
Therefore, in the winding of the optical fiber 11 on the narrow width winding portion 21 using the bobbin 20 having the narrow width winding portion 21 shown in FIG. 24, manual operation is necessary. In particular, the terminal of the optical fiber 11 is manually introduced to the narrow width winding portion 21 through a through hole (not shown) for guiding the fiber which is formed on a base end portion of the first flange portion 25A, and thus, the optical fiber 11 is wound around the narrow width winding portion 23. Thereafter, the terminal of the optical fiber 11 is fixed. That is, although the fixing operation of the terminal of the optical fiber 11 and the winding operation on the wide width winding portion 21 can be automatized, the winding on the narrow width winding portion 21 cannot be automatized. Accordingly, the winding of the optical fiber 11 on the narrow width winding portion 21 is a big problem with respect to labor-saving in the winding process in regard to the overall automation of the optical fiber winding, and productivity improvement.
In addition, in the above, the case where both of the first winding portion (narrow width winding portion) 21 having a very narrow width W1 and the second winding portion (wide width winding portion) 23 having a wider width W2 are formed on one bobbin 20 is described. However, even though the bobbin is a bobbin having only one winding portion, when the width of the winding portion is significantly narrow, the above-described problem occurs.